Air heater



June 8, 1937. J. F. HERBERT AIR HEATER 2 Sheets-Sheet `1 Filed March 5A, 1956 June 8, 1937, J. F. HERBERT AIR HEATER Filed March 5, `1936 2 Sheets-Sheet 2 v Patented lJune 8, I v1937 attains am usaran. Y i Josephl Herbert,- Audubon, N. J. Application man s, 193s, semi No. 66,909

' achim. 4 (clics-11o) Thisl invention relates to the class of hot air furnaces and pertains particularly to an air he'ating furnace .of the forced air circulating type to be used in conjunction with anyltype of heating means, such as a pressure type domestic fuel oil bumer or the like. A primary object of the present invention is to provide an improved air heater of compact design which is capable of emciently heating large 1'0 quantities of air andat the same time because o1' its compactness being adapted to be moved about.

- another object ofthe invention is to provide an improved air heating furnace having a novel heat transfer unit whereby the maximum heat units of the fuel employed will be extracted from `the burning fuel gases;

A stili further object of the invention is to prode a novel air heating furnace wherein the air 2o to be heated is forced to move downwardly between air transfer plates of hollow construction, through which plates the products of fuel combustion pass upwardly, and wherein the downwardly flowing air is divided anda portion of it passed across a water container so that thev air will behumidied.

A still further obiect of the invention is to provide an air heating furnace having built thereinto an air circulating unit whereby unheated air will be drawn in and circulated through the heat transfer-portion of the structure and discharged from the furnace directly into the room in which the furnace is placed or into distributing pipes as desired.

5 The invention will be best understood froma consideration of the followingdetailed descrip tion taken in connection with the accompanying drawlngs,.with the understanding that the invention may be changed or modified so long as such changes or modications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings Figure 1 is aview in elevation of a. furnace structure embodying the present invention;

Figure 2 is a vertical sectional view taken on the line' 2 2 of Figure 3;

IFigurev 3 is 4a sectional view taken on the line 3 3 of Figure 2; l 5,) Figure 4vis a horizontal section taken on the Ifnet- 4 of Flgiu'e 2;

Figure 5 is asection on the line l-I of Figlll't? 2; Figs. 6 and 7 are sectional views taken re- 55 spectively on line t-l 'and 'I-l of Fig. 2.

Referring now more particularly to the drawings wherein like numerals o f reference indicate corresponding parts throughout the several views, the.l numeral I indicates generally the body or housing of the furnace structure embodying the 5 presentV invention, the same belnglpreferably of rectangular cross section as illustrated and having a front wall 2 provided with the plate# through the center of which an aperture is formed for the introduction o f a fuel burner nozzle l. 16

'Ihe wall construction of the furnace body I may be of any suitable type, such as metal having an insulation outer covering asis commonly eml ployed.

Secured in the lower part of the body'of the 15 furnace housing is a floor 5 which extends from the front wall 2 to a point short of the back wall 6 thus leaving an area. 'l bordered on one side by the back wall 6 and atthe two ends by the side walls 8 and at the front by a low upstanding wall 20 9 which is formed integral with thel bottom or floor 5 at its back edge and which extends the full width of the furnace. 'I'he bottom wall I- is of a width at its rear equal to the interior width of the furnace structure and tapers slightly toward the frontas illustrated in Figure 4, andv thus leaving open side areas I Il. These tapering sides of the bottom have vertical walls II formed integral therewith andare connected by a top wall I2 which, as shown in Figure 2, slopes up- 30y wardiy through half of its length from the front wall of the furnace structure toward the back and is then inclined downwardly at a sharp inclination to meet the hanging baille wall I3 which has its lower edge spaced from the bottom I and which is in spaced relation with the wall 9. There 'is thus formed the fire boxor combustion` area I I and, as shown in Rigure 2the fuel burner nozzle 4 is directed toward the lower part of the hanging wall Il and against the downwardly' inclined =40 under .sidev of the back part of the top wall I2.

Extending transversely o f the furnace floor in the ire box I4 is an adjustably positioned 11p-- standing baille wall I 0 which is placed forwardly of the wall I3 so that suitable passagewayis providedv for the escape of products ofcombustioninto the area between the walls 9 and Il vat the back part of the furnace. y The position of this baille wall I 8 is regulated when the heatingstructure is installed for use.

Opening through one side o'f the furnace structure and through a wall II, is a passage forming structure I1 which opens-into the -re box -at one endand which has 'its outer end closed by lthe gravity Ccontrolled door Il; -Tl ns.structure vg55 I1 provides anl escape for any suddenly developed pressure in the fire box Il such as might occur if an excess of gas collected in the box and was suddenly ignited so that the suddenly developed pressure therein could not conveniently escapeA through the usual gas escape passages.

Arranged above the top wall or roof |2 of the combustion' chamber Il is a horiaontal wall It which extends across the width of the furnace structure and which is joined at its front edge with the lower edge of a vertical inner iront wall '2l and at its back edge with a vertical inner rear wall 2|. 'Ihe area between the wall i9 and the roof 2 of the combustion chamber to- 15 gether with the area between the inner front wall 2l and the outer iront wall 2 of the structure form together a hot air escape passage which is indicated by the numeral 22, and this passage is in communication with the areas i0 at'the sides of the combustion chamber.

. 'Ihe area between the inner walls 2li and 2| and the wall Il, forms a chamber 22 thetop of which is covered by the top wail- 24 of the furnace structure and this top wall has an open- 25 ing therein in which is removably iltted a frame 2l which is filled with a suitable air cleaning or illtering material of non-combustible character such as steel wool or the like which is designated by the numeral 28. Within the chamber 23, which constitutes the fan and motor housing, is an electric motor 21 and a fan 2l, the air intake side of which opens into the housing or chamber 2l while the discharge pipe 28 thereof opens ,through the inner rear wall 2| into the area lying between this wen and the beek wen s.

Disposed in the area between the walls 2| and C is a heat exchange unit which is generally designated by the numeral I0 and which comprises a plurality of ilat tubes 3| arranged in relative ly close side by side relation and maintained in the desired spaced relation by the ribs l2 which are pressed outwardly from the side walls thereof throughout a portion of the length of the walls, as illustrated in Figures 2 and 5. The areas between these flat tubes are closed at the top end of the unit while the top ends of the tubes are open'and these top ends are cut at an incline as shown in Figure 2 so as to discharge into the area I2 which is in communication with the ilue or gasoutlet 24. The lower ends of the tubes open into the area between the walls 0 and i3 and receive the products of combustion passing from the combustion chamber Il beneath the baille wall Il. As shown in Figure 2, the lower ends of the tubes Il are cut into an inverted V, as indicated at Ii, and the areas between the lower ends of the tubes are closed by the V- shaped walls 2l. One side of the V-shaped cut out portion I5 terminates short of the rear edges 00 of the tubes and rests upon the top of the wall l. It will thus be seen that there remains a portion of each tube 2| which extends across the area of the wall l and the back wall I and this remaining portion of the lower end of each tube is closed but the space between the tubes over this portion is left open. From this it will be apparent that air driven by the fan- 2l through the openingy in the top of the wall 2| into the areas between the tubes, will flow downwardly until it strikes the dividing plates le between the tubes whereupon a portion of it will be denected by the plates l* into the passageway 22 which leads across the top wall |2 of the combustion chamber and another portion will flow downwards,oss,4os

1y between the tubes inte the aree 1 beneath the bottom wall l. This bottom wall l is provided with a plurality of fins I1 which, as illus- :trated in Figure 4, are curved to guide the air forwardly .to the areas il `from which it will flow upwardly into face of the wall 0 also has vertically arranged fins ll thereon which keep the air spread out and prevent it flowing in a narrow path.

The back wall 6 of the furnace structure is provided with an opening Il fcr'th'e introduction into the area beneath the bottom l of the combustion chamber, of a pan Iii which has an open top and which is intended to contain water at all times while the furnace is in operation.

the passage, and the back sur- This pan has its top spaced from the lower edges of the air guiding fins I1 and is adapted to have its top closed vby a suitable means, such as a plurality of louver blades 4| which are oscillatably mounted therein and which may be controlled by a suitable lever l2 which may be manually actuated or may have any suitable mechanical means connected therewith for effecting this actuation in accordance with the degree' of humidity of the air of the room in which the furnace is located.

In the area lying yat the rear of the combustion chamber Il and defined by the vertical walls l and I3, there may be located. a suitable pipe or coil 4l for heating water for domestic use and also located in this area is a burner M of the type suitable for burning fuel gases. This burner may be used as an auxiliary to the burner which has its nozzle l extended through the front wall of the combustion hamber in the event that the liquid fuel burning t breaks downor has to be kept out of use for any reason during a period when it is necessary that the furnace be kept in operation.

At one end of the area into which the combustion chamber discharges, the wall of the furnace is provided with an opening Il which is covered by a door 4i and which provides a means for cleaning out this portion oi' the furnace or for reaching the burner 44 or water pipe Il if occasion demanda. The top wall 24 is provided with anopening over the area in which the tubes 2| are disposed which is covered by a removable door 2l'. By means of this opening the areas between the tubes may be reached for cleaning. In order that the air flowing downwardly between the nat tubes Il and into the area over the roof of the fire box or combustion chamber Il may be kept spread out so as to pick up as much 'heat as possible from the fire box. the roof of the ilre box is provided with a series of ilns I1. 'nie wall 2|, in addition to having the opening at its top for the passage of air therethrough by the fan 2l, also has an opening or openings in its lower portion which discharge from the areas between the tubes Il into the area between the combustion chamber wall |2 and the inner horizontal wall structure Il.

The material 2l in the air inlet openingleading to the fan chamber 2l may be of any suitable character to clean the air. One method which may be employed ,is to saturate the steel wool 2i with oil so. that the air passing therethrough will have any dust particles picked im extracted therefrom and will pass between the iiues of the heat exchanger in a clean condition.

Whilethe description and illustration have been .confined to the furnace structure per se it will be obvious that the operation of the same may be readily controlled by any of the automatic devices sessies at present on the market for governing the o tion of furnaces so. that when the air within the furnace reaches a predetermined temperature the burner operationmay be shut down or shut` 'oiI as required and also when the room temperature reaches the desired degree the operation of the furnace may be completely shut oif. For the control of the burner mechanism in accordance with the nue temperature of the furnace, there is shown in connection with Figures 1 and 3 a thermostat device which is indicated by the numeral ,lll These control devices for the burner and for the air circulating blower may be so arranged that when the controlling room thermostat calls for heat, the burner mechanism and the air blowing mechanism ,will start operating. When the heated air within the furnace reaches approximately 230, the control device 2l will shut oil the burner but the air circulating device will' continue to operate to force the heated air from the passage 22 until the air temperature in the'furnace d rops to approximately 200. At this point the burner will again be started up and thesecycles will continue until the desired room temperature is reached after which the rooiii thermostat will operate to shut of! the burner and the air circulating fan or blower will operate until the furnace temperature drops to 90.when ittoo will cease operating.

I claimz- 30 1. In an air heatena housing body, a fuel combustion chamber disposed in saidbody andv having top, bottom and side walls, saidside walls being in spaced relation with the side walls 'of the housing body whereby air may flow from beneath the combustion chamber to the space above the same. an upwardly directed outlet to the rear of said com- 'bustion chamber, an inner r'ear wall in said housing body extending upwardly through the housing body from the combustion chamber at one side of said outlet and forming with the housing body rear wall a .vertically extending chamber into 1 which said outlet isdirected, .a heat transfer unit comprising a plurality of vertically disposed ilat -tubes arranged in spaced relation in said chainber between the housing body rear wall and the inner rear wall and over said outlet, said inner rear wall having openings leading therethrough from the spaces between the tubes to the space over the top wall of the combustion chamber, said tubes being 'open at their upperand lower ends for the passage of products of combustion therethrough, means closing the spaces between the tubes at the upper and lower ends thereof,- means for forcing air downwardly between thetubesfor discharge onto the top wall of the combustion chamber, means for leading of! the products of combustion from the upper ends of the tubes, l means. for leading oil! the heated air from the.

60 2. An air heater comprising a housing. a com. bustion chamber in the lower part of said which includes a bottom wall, side walls and a topf wall, said side walls being partly in spaced relav A `tion with the Vside wallsof the hllsln. Said bot.-

tom wall being spaced from the bottom fof the. housing terminating short of the back wall of the housing and having an ultanding wall spaced from the housingy back wall. said top wall terminating short of the upstanding lwall to form. an outlet for the combustion chamber, a wall'extending transversely of the housing over and in spaced relation with .the top wall of the combustion chamber' and forming a horizontal air passageway therewith, a vertical wall extending from 75 said transverse well upwardly in spaced relation Ling a combustion chamber having a top wall a plurality of spaced flat tubes inv said other whichv are open at their ends and form vproducts of combustion conducting meansibe- .tween the combustion chamber outlet and an with said housing back wall, a plurality of flat tubes disposed in spacedV side by side relation between said vertical wall and the housingback wall over the said outlet, said tubes being open at their upper and lower ends and receiving products of 5 combustion in their lower ends, means closing the spaces between thetubes at the upper ends. means closing the areas between the tubes vat their lower ends from the terminal edge of the top wall transversely to said upstanding wall, the spaces between the lower ends of the tub'es being open between the said upstanding wall and the back wall of the housing, means for creating a downward flow of air between the tubes for discharge therefrom into said air passageway, a portion of the air being delivered to the space between the housing back wall and said upstanding wall to flow beneath and up over the sides of the combustion chamber. means for carrying olf theproducts of combustion from the upper ends of the tubes, and hot air outlet means for the housing.

3. In an air heater, a casing having a vertical chamber, means formingva combustion inithe lower part of the-casing vandina 25 outlet directed upwardly into the lower part the first chamber, said first chamber havipgfsff; products of combustion outlet .at the upper *part thereof, a plurality ofvertically arranged broad nat tubes in tnecnambea which temumteiarla their lower endsover andextenrl across said com-y bustion chamber-outlet, the tubes being spaced.: apart andhaving their ends open, means closing" the spaces between the tubesl at the ends thereof, a heated air outlet at an elevation above the combustion chamber, means for forcing airfinto' the spaces between the tubeseadjacent the tops' thereof, and means between the lower ends the tubes for dividing the path of air travel into two streams over the `outside of and above and below the combustion chamber to the heated air outlet. g Y -v 4. In an air heater, al casing, a pair of vertically arranged spaced walls therein and a hori-y zontal wall connecting the spacedwalls whereby to form a center chamber and two vertical side chambers, one of said side chambers constituting a heated air passage having an outlet, said side chambers opening into the lower part of the casing beneath said horizontal wall, means fon'm spaced from said horizontal wall andan outlet directed upwardly into the other sidechamber,

outietyatjthe upper part of the said other side rfcha'lnber, said tubes having the, spaces between .their ends closed, and lmeans in saidA Ycenter chamber. A'for rforcing air fdo'wnwardly, through the spaces between the-:tubes lfor discharge therefrom intorthe space between the horizontal wall and. said top wall and thence to said heated air passage. v y

' '5. In an air heater,'a. casing.' a pairy of vertically arranged spaced walls therein and ahorizontal wall connecting the spaced walls whereby to form a center chamber and two vertical side chambers, one of said side chambers constituting a heatedv air e having an outlet. said side chambers opening into the lower Dart of the casing beneath said horizontal wall. means forming a combustion chamber having a top wall spaced from said horizontal wall and an outlet 75 directed upwardly into the other side chamber. a plurality of spaced flat tubes in -said other chamberwhich are open at products ofvcornbustion conducting means between the combustion chamber outlet andan outlet at the' upper part of the .said other side chamber, said tubes having the .spaces between zontal wall connecting the spaced walls whereby to form a center chamber and two vertical side chambers, one of said side chambers constituting a heated ,air passage having an outlet, said side chambers opening into the lower part of the casing beneath said horizontal wall, means forming a combustion chamber spaced from said horizontal wall and an outlet directed upwardly into the other side chamber, said last outlet being adjacent a rear wall ofthe combustion chamber and said rear wall being spaced from a wall of the casing forming there'- with a passage leading downwardly from said other chamber to a space beneath the combustion chamber, a plurality of spaced fiat products of combustionconducting tubes extending vertically in the said other chamber in the top oi said rear wall and having their lower edges extending across the same, the ends of the tubes being open, means closing the spaces between the upper ends of the tubes through the entire width of the tubes, means closing the spaces between the lower ends of the tubes only from one side of said combustion chamberl outlet to their ends and form and ythence to spaced' relation with the ing area'r wall in spaced relation with the casrear extending Y having a top wall l y bustion chamber outlet to thegotherffthe spaces between the tubes at the lower'ends thereof opening into the-space between said,qjhorizontalf4 wall vand l said topwall, and

means in center chamber, i'orforcing 4air downwardly throughthe spaces between the tubes the space above and beneath the andto the heated air pascombustion sage.v

7. Inan air heater,"a casinghaving back, bottom and side walls, a combustion chamber disposed within the lower part of the casing in bottom wall and having back wall,rsaid` chamber n the full' width ofthe casing between the side walls, air passageways betweenl the sides oi the chamber andthe side walls oi the casing. said combustion chamber having anlupwardly directed -outlet immediately adjacent its rear wall,

a vertical chamber extending the full width of the casing between the side walls and having an outlet at its upper end and having the combustion ,chamber outlet di-rected upwardly thereinto, means forming a plurality of products of combustion" conducting passages from said comthe vertical chamber outlet, air conducting passages alternating with said first passages', `means for effecting a down flow of air through the airconducting passages, means in the lower ends of the air conducting passages for deflecting the vdown ilowing air in two streams one of which passes over said combustion chamber passes downwardly between the combustion chamber rear wall and the casing back wall to thev area beneath the combustion chamber, .and a warm air outlet from the casing at an elevation above the combustion chamber, the air passing beneath the combustion chamber flowing to said last voutlet by way of the passages at the sides of the combustion chamber.

. JOSEPH F. HERBERT.

and ,the other of which 

